Data de-duplication systems parse an incident data stream into blocks, compute an identifier (e.g., fingerprint) for a block, and selectively store unique blocks in a block repository. Data de-duplication systems also satisfy read requests that seek to read data from unique blocks in the block repository. Conventional data de-duplication apparatus and methods may use a dual purpose buffer to track buffer pages. The dual purpose buffer may be managed using a least recently used (LRU) data structure that can track pages that are used both for satisfying ingesting data actions and for satisfying read requests. Conventional data de-duplication apparatus and methods may prioritize processing ingest actions over satisfying read requests. Thus, conditions may arise where a read request may never be satisfied, or may be satisfied in an unacceptably long or undesirably long period of time.